Light bulb



FIG. 1 is a front, top perspective view of a light bulb;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a left-side elevation view thereof;

FIG. 5 is a right-side elevation view thereof;

FIG. 6 is a back elevation view thereof;

FIG. 7 is a front elevation view thereof; and,

FIG. 8 is an enlarged view of an area marked 8 in FIG. 2.

The dashed broken lines depict portions of the light bulb that form no part of the claimed design. 

CLAIM The ornamental design for a light bulb, as shown and described. 